Perturbed myelo/erythropoiesis is transplantable with Lyn^-/- BM. (A) BM from C57BL/6 Ly5.2 background donor Lyn^+/+ or Lyn^-/- mice was transplanted into irradiated C57BL/6 Ly5.1 mice. Engraftment was assessed by identifying donor and recipient cells by FACS analysis with CD45.2 (donor) and CD45.1 (recipient) mAbs. Alternatively, immature erythroid lineage cells in spleen and BM were assessed by staining with CD71 and Ter119 mAbs. Both PI-positive and mature RBCs were excluded from the analysis. The relative percentages of each population (± SD) in 4 recipient mice of each genotype are presented. (B) CFU-e and BFU-e content in the spleen and BM of recipients of either Lyn^+/+ or Lyn^-/- BM are shown. (C) The relative number of CD71/Ter119 double-positive erythroid cells in spleen and BM assessed 10 to 12 weeks after transplantation. (D) Myeloid progenitors in spleen, BM, and peripheral blood responsive to the indicated cytokines were determined in mice reconstituted with either Lyn^+/+ or Lyn^-/- BM. Progenitors were scored following plating of 10⁵ spleen cells, 2.5 × 10⁵ BM cells, or 1 to 2 μL peripheral blood. Data presented in panels B and D correspond to the mean (± SEM) for 3 experiments using 2 mice/experiment (^*P < .01, Student t test). Data presented in panel C were obtained from the analysis of 4 mice in 2 experiments (mean ± SEM).